taking center stage tonight. His fierce followers have seized large parts of Iraq and they have a lot of money and Venn gang in their words. Tonight, their threats have the U.S. And the west increasing security on airplanes and ABC's chief investigative correspondent Brian Ross is on this story. Reporter: Not since Osama bin laden has any terror leader caused so much concern for the United States, with his simultaneous terror threats and battlefield successes. In this new video, posted online over the weekend, the once camera shy 43-year-old Iraqi Syrian jihadist Abu Bakr Al baghdadi, flashing an expensive watch, raised the stakes claiming he was the new mriprince of the Muslim world. "I have been plagued with this great responsibility," he said in a sermon in the captured city of mosul. Some believe success has gone to his head. Most muslims, almost all muslims around the word are horrified at that. Reporter: But Al baghdadi's threat to create an islamic state is backed by thousands of fighters from around the world, including the U.S. And millions of dollars. And in a stunning military campaign, his group has either rapidly seized or has an operational presence in a wide swath of territory across Iraq and Syria about the distance from Chicago to Washington, D.C. A place officials said today could become a launching pad for attacks on the U.S. We're concerned that these threats and what's happening in the region could pose a threat to the United States. Reporter: And now, American officials say they fear a threat to u.s.-bound aircraft from jihadists with western passports now in Syria and Iraq, carrying bombs designed by a master Al Qaeda bomb maker. The threat is real. It is strong. And clearly the U.S. Is the number one target. Reporter: U.s. Intelligence reports indication the bombs could be carried in electronics. So, that's why travelers on select flights into the U.S. From overseas are being told they must turn on their electronic devices at security checkpoints before boarding flights. The enhanced security steps were put in place over the weekend across the middle east and Europe, including today at London's heathrow airport. Flights into the united States. Reporter: Direct fleekt. You have to be able to turn it on. Okay, thank you, Brian Ross. And now, we turn to the ancient hatred in the middle

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